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2 Consecutive 'Single Yellow' Aspects at Barnetby

You are here: Home > Forum > Simulations > Released > South Humberside > 2 Consecutive 'Single Yellow' Aspects at Barnetby

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2 Consecutive 'Single Yellow' Aspects at Barnetby 05/07/2012 at 01:29 #33646
Aurora
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A simpler question (I think), when the route has been cleared, why are there two consecutive single yellow aspects on the Down Fast line at Barnetby?



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Last edited: 05/07/2012 at 01:47 by Aurora
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Re: 2 Consecutive 'Single Yellow' Aspects at Barnetby 05/07/2012 at 07:40 #33647
jc92
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both signals in question are semaphore, and both carry a distant signal for wrawby junction. these were fixed at caution circa 1970 i think. possibly later. therefore these signals can never display anything greater than a yellow aspect. the reason there is two is the short distance between the two. when originally installed, the inner distant would have provided insufficient braking distance, so an additional outer distant was provided at full braking distance.

these signals are fixed due to the low speed through the turnouts towards scunthorpe and lincoln (think approach control to red in MAS areas)

"We don't stop camborne wednesdays"
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Re: 2 Consecutive 'Single Yellow' Aspects at Barnetby 05/07/2012 at 11:07 #33652
Steamer
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jc92 said:
therefore these signals can never display anything greater than a yellow aspect

In the sim they will clear in both eras if a route is set through to Brigg.

"Don't stress/ relax/ let life roll off your backs./ Except for death and paying taxes/ everything in life.../ is only for now." (Avenue Q)
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Re: 2 Consecutive 'Single Yellow' Aspects at Barnetby 05/07/2012 at 11:24 #33655
DriverCurran
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Rule book module GERT8000 TS1 clauses 4.6.1 and 4.6.2 are being applied to these signals

Paul

You have to get a red before you can get any other colour
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Re: 2 Consecutive 'Single Yellow' Aspects at Barnetby 05/07/2012 at 11:29 #33656
Danny252
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" said:
Rule book module GERT8000 TS1 clauses 4.6.1 and 4.6.2 are being applied to these signals

Paul
In short, no they aren't - all of Barnetby East's signals are clear. If it was actually the case, the rules would be being applied completely wrongly, as the distant and home are both clear.

Last edited: 05/07/2012 at 11:30 by Danny252
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Re: 2 Consecutive 'Single Yellow' Aspects at Barnetby 05/07/2012 at 11:36 #33657
Late Turn
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In reality, Wrawby Junction's Down Fast Outer Distant (WJ132, located under BE50) and Down Fast Inner Distant (WJ124, located under BE49) aren't actually fixed at Caution. When I last visited though, both appeared to be signed out of use (presumably because they'd been neither used nor maintained for years!). I've seen photos showing them cleared as late as the 1990s though.

As Danny says, all of Barnetby East's stop signals are cleared (51, 50 and 49), and the Down Main Distant (52) is also off. TS1 clauses 4.6.1 and 4.6.2 are therefore not being applied to any of those signals.

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Re: 2 Consecutive 'Single Yellow' Aspects at Barnetby 05/07/2012 at 12:29 #33660
Danny252
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The distants only apply to the Brigg line, but yes, they are (or were!) signed out of use as of 2010.
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Re: 2 Consecutive 'Single Yellow' Aspects at Barnetby 05/07/2012 at 13:31 #33661
jc92
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" said:
The distants only apply to the Brigg line, but yes, they are (or were!) signed out of use as of 2010.
the distants apply to Wrawby junctions home signal, and all routes radiating from it. they have been signed out of use a lot longer than 2010, as late turn points out. they are actually still connected, but locked at danger

"We don't stop camborne wednesdays"
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Re: 2 Consecutive 'Single Yellow' Aspects at Barnetby 05/07/2012 at 13:41 #33662
Danny252
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" said:
the distants apply to Wrawby junctions home signal, and all routes radiating from it
The signalmen there would beg to differ:

WJ 132 down fast Gainsborough outer distant, 124 down fast gainsborough inner distant and 120 down slow gainsborough distant [...] they only apply to the Brigg line

http://www.signalbox.org/forum/viewtopic.php?f=5&t=2682

Last edited: 05/07/2012 at 13:41 by Danny252
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Re: 2 Consecutive 'Single Yellow' Aspects at Barnetby 05/07/2012 at 13:43 #33663
Late Turn
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Sorry, I forgot to mention in my previous post that they do indeed only read to the Brigg line. The pull plate on lever 124 reads "Down Fast Inner Distant to Gainsborough (124,115)", supporting that. 132 (the Outer Distant), in turns, requires 124. They were collared in the box at the time of my visit.
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Re: 2 Consecutive 'Single Yellow' Aspects at Barnetby 05/07/2012 at 13:55 #33664
onlydjw
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I'm going to go right back to basics as best as I can, as I've had a couple of PM's on this topic before I've had chance to see it.

If it hasn't become obvious from the replies already, the way the sim represents semaphore signalling is not necessarily the most obvious from the "outside" - I shall do my best to explain. With a standard stop signal - it can show 'on' or 'off' - that being red or green in simsig, and therefore is simulated as a 2 aspect signal. In the cast of the two signals questioned, they have a stop signal with a distant underneath. The stop signal effectively shows red or green, and the distant yellow or green. For simsig, this is simplified to red, yellow or green (green only showing as if both signals were cleared). However, unlike standard MAS (Multiple Aspect Signalling), the distant signals refer to whether or not the whole of the following section is clear (ie in this case, whether all the corresponding signals controlled by Wrawby Jn are cleared). In real life, Barnetby East pulls the stop signal (in simsig from red to yellow), and Wrawby Jn pulls 'his' stop signsls 'off' and then pulls the distant signal (in simsig this happens automatically once the complete route is set through Wrawby Jn). The other thing you will note is that if only part of the route is set in simsig through each section which is simulating semaphores, that the route sets, but the signals don't clear until the train is approaching them. This "approach control" simulates the reality that the semaphore is not cleared until the train has reduced speed, to caution the driver that the next section (to the next signal box) is not yet clear.

The references to the pages of the rule book will also help, but hopefully that gives a bit of a guide without being too technical, and relates it back to how simsig works.

Now to the main question and comments/answers already given:

From visits last year, there are no "operational" (ie moveable) semaphore distant signals in the Barnetby area (there or Wrawby Jn). For some years they were not signed out of use, but did not physically work. Today they are signed out of use, although mainly due to the mechanical state of them, and the cost of repair being prohibitive, given the distant signals only used to clear if the route was set towards Brigg, the relative traffic level compared with the Scunthorpe route, the speed restrictions across the junction (there nearly always eesm to be a TSR), and the proposed resignalling which may or may not happen within the originally stated timescales which have already slipped!

Barnetby East's distants are now all colour light singals, but those sections which contain semaphores do require all of them on the corresponding route to be clear, without involving any crossover moves (that's the easiest way to explain). Those distant signals which correspond to the IBH signals near New Barnetby (or those which effectively act as an IBH signal in the case of BE22), which are numbered BExxR in both reality and simsig, do not have their own levers, and therefore work automatically to the stop signal the number corresponds to, just as you would expect with MAS.

I should point out that the original release (2.218.76) did not quite have the distant opeation correct - this has now been fixed for release once Chris and his team are happy with the project (no timescale available at this stage). In basic terms, they will not clear in modern mode, but will if the route is accordingly set towards Brigg (and not via any of the crossover points), and this is how the next version of the sim will be set (hopefully)!

Hopefully that has answered the questions I've been asked via PM, and helps a bit towards the exisiting topic as well. If there's any further questions, I'll do my best to answer them (or others will).

p.s. The link posted www.signalbox.org/forum/viewtopic.php?f=5&t=2682 should be spot on, given it was written by a Barnetby East signaller, and explains the BE22 situation rather well, as well as adding a bit more to what I've put.

God bless, Daniel Wilson
Last edited: 05/07/2012 at 13:59 by onlydjw
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Re: 2 Consecutive 'Single Yellow' Aspects at Barnetby 05/07/2012 at 14:19 #33665
Late Turn
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" said:
The other thing you will note is that if only part of the route is set in simsig through each section which is simulating semaphores, that the route sets, but the signals don't clear until the train is approaching them. This "approach control" simulates the reality that the semaphore is not cleared until the train has reduced speed, to caution the driver that the next section (to the next signal box) is not yet clear.

A handy example of how TS1 Clauses 4.6.1 and 4.6.2 (referred to earlier in this thread) are applied in the sim. For completeness, the following the actual wording:
Quote:
4.6 Clearing a stop signal when the next signal is at danger

4.6.1
If you cannot clear a stop signal, you must not clear any associated signals on the approach to it until the train has stopped or nearly stopped at each signal in turn.

4.6.2
You do not need to apply this instruction if the stop signal on the approach to the stop signal at danger is a colour light that can show a yellow aspect, and:
• is controlled by the occupation of a berth track circuit, or
• requires the line to be clear up to and including the overlap track circuit of the signal at danger.

Perhaps the easiest way to understand the operation of a distant signal reading to a semaphore stop signal is to consider the significance of the term 'station limits' (the distance between the outermost home signal and the section signal) - with a few exceptions where things are more complex, all signals within station limits must be cleared before the distant can be cleared, and then (usually) only for the straight route. Beyond station limits is the 'block section' (or intermediate block section), where the process starts again with the distant for the next box (or intermediate block home).

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Re: 2 Consecutive 'Single Yellow' Aspects at Barnetby 05/07/2012 at 15:56 #33669
jc92
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" said:
" said:
the distants apply to Wrawby junctions home signal, and all routes radiating from it
The signalmen there would beg to differ:

WJ 132 down fast Gainsborough outer distant, 124 down fast gainsborough inner distant and 120 down slow gainsborough distant [...] they only apply to the Brigg line

http://www.signalbox.org/forum/viewtopic.php?f=5&t=2682
thats just wording as far as im concerned, the distant signal applies to the bracket signal acting as wrawbys down home, you cant have a home without a corresponding distant signal, unless two boxes are sharing a distant signal. it still provides a warning that the signal for the lincoln and scunthorpe routes are at/may be at danger

"We don't stop camborne wednesdays"
Last edited: 05/07/2012 at 15:59 by jc92
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Re: 2 Consecutive 'Single Yellow' Aspects at Barnetby 05/07/2012 at 17:57 #33670
Late Turn
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Ah, I see - and quite right, of course. What we're all getting at (and I'm sure you agree) is that the distants in question won't come off for any route other than straight on to Brigg!
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